1. Field of the Invention
Aspects of the present invention relate to an image forming apparatus having a duplex automatic document feeding (DADF) function and a control method thereof, and more particularly, to an image forming apparatus having a duplex automatic document feeding (DADF) function in order to automatically re-scan a document through a duplex path thereof, and a control method thereof.
2. Description of the Related Art
An automatic document feeding (ADF) device, when used for copying a plurality of document sheets, for example, enables continuous feeding of the plurality of document sheets one by one and copying of the fed sheets. Image forming apparatuses having such a duplex ADF (DADF) device have become widespread, enabling duplex copying and scanning operations.
When a user desires to copy a document, a conventional image forming apparatus having a DADF device feeds a document, scans the fed document, reads image data from the scanned document, and temporarily stores the read image data in a buffer. The temporarily stored image data is moved to another memory and converted into printable data. During a scanning operation of the document, if the buffer becomes full, the conventional image forming apparatus deletes image data stored in the buffer, and scans the following document, namely, another page. Alternatively, the conventional image forming apparatus stops driving a motor for copying, waits until image data can be stored in the buffer, and then re-scans the document.
However, when the conventional image forming apparatus deletes the image data, as described above, a user needs to manually place the document on a feeding path to scan the document whose image data has been deleted, which causes user inconvenience. Additionally, re-scanning the document from a portion where the buffer becomes full after stopping the motor causes an image quality to be reduced due to, for example, jitter. In particular, when scanning a document at a high speed, it is difficult to control the jitter, causing a large decrease in the image quality.